HI, my new second hand 4ft fish tank has a 1cm circular crack on the upper middle, inside only. Does anyone know of this is a problem? Ive just noticed it and the guy i bought it from goes o/s tomorrow
Hello and welcome Di
If it leaks then it is a problem, if not its not. If your worried get your money back before the guy does a runner. 
(everyone I know have a small crack (some bigger) but this doesnt seem to be a problem) 
